Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–3
Up to 3 feet of dense snow combined with strong winds over the last 5 days have created dangerous conditions. New and recent snow has formed slabs 2-4 feet thick that when triggered can propagate across large distances and make escape impossible. Obvious signs such as cracking and collapsing may not be present. Large triggers, terrain over 35 degrees, and warm temps are factors that will increase the odds of triggering an avalanche today. Keep terrain choices simple by sticking to lower angled terrain and be especially wary of the creekbeds and flat terrain that create unsurvivable terrain traps.
Weak snow near the base of the snowpack lurks 2-5 feet below the surface. New snow and warm temperatures are stressing these weak layers. Avalanches involving these layers could occur with a significant trigger such as a large wind slab avalanche, a passing snowmobile or even a group gathered below a slope.